Both caffeine and sugar are common dietary substances that have been implicated in behavioral and cognitive deficits in a variety of adult populations. The effects of these substances on normal and behaviorally deviant children are being studied in an ongoing series of studies. Caffeine in relatively high doses (10mg/kg) may increase nervousness and insomnia as well as worsen classroom behavior. However, preliminary evidence indicates that children who habitually self select high caffeine diets are not adversely affected and may even benefit from caffeine. Current studies of behavioral response to glucose, sucrose and artificial sweetener placebo do not show any significant behavioral effects on grade school children thought to be sensitive to sugar.